Art of and apparatus for drying materials



@est 9 1923 j 1,470,306 J. H, WALSH ART OF AND APPARATUS FOR DRYING MATERIALS Filed Oct. 15. 1919 4 Sheets-Sheet 1 Mmm@ 1919 4; Sheets-Sheet' 2 @et 9 llQZE.

J. H. WALSH ART OF AND APPARATUS FOR DRYING MATERIALS Filed 0G13. 15

J. H. WALSH ART OF AND APPARATUS FOR DHYING MATERIALS Filed oct. 15; 1919 4 sneets-sheet s 'D U QE@ .M a? M0@ www@ @et 9 l923 J H WALSH ART 0F AND APPARATUS FOR DRYING MATERIALS Filed oct. 15. 1919 4 Sheets-Sheet 4 LU e7 U60 7 l 7 se?) 08872,

neme caga 19239 e i' UNITED .STATES PATENToFFicE,

, JOSEPHH. WAVLSH, .OF READING, MASSACHUSETTS, ASSIGNOE T JOHNS-MANVILLE INCORPORATED, OF YORK, N. Y., A CORPORATION OF NEW YORK.

ABT 0F ANU-APPARATUS FOR-DRYING MATERIALS.

Application ala october 15, 191s.- seriai No'. 330,813.

Apparatus for Drying Materials, of whichr the following is a specification. t

This invention relates to an art of and ap-A `il@ paratus for treating material, and moreparticularly to the art of dryin materials, and to apparatus applicable to this and other purposes. By drying, reference is made to removing from the materials [which may t comprise cloth, fibrous stock of 'textile ,ma-

terials, or any. raw or manufactured bulk capable of handling in a sheet or stream] by evaporation, vaporization or boiling either Water or any vehicle or solvent in E@ or upon the material; for instance, for removing mere dampness, or Wash-Water, or -a volatile liquid, or the aqueous content of acid or alkaline solutions o r chemical reagents employed in carbonizing treatments Q5 of textile fibre or cloth.

Referring now for an instance only to the treatment of cloth as heretofore practiced, so far as ll 'am aware, the common drying step for merely removing moisture ao from cloth previously subjected to Washing,

ulling, Soaping, bleaching, dyeing, tentering, rigging, straightening or steaming operations, has comprised subjecting the cloth to intense radiated heat from hot pipes 86 grids or plates, standing near runs oi the cloth traveling on suitable carriers in a suitable serpentine path in some form of drying machine. The wet cloth entering the machine is thus subjected to a relatively do high surface temperature, generally of 'the order of 235 F. or higher, the result being partly to evaporate and partl to boil the moisture in the cloth out of t e cloth, and frequently being to 'damage the cloth either to by the explosive action Vof steam from its contained moisture or by subjection of one or bot-h faces to too-intense radiated.heat.

@ne consequence of treatment vin this manner has been to subject the cloth in such a w machine or during such a step in the process of treating it, to the wet steam or vaporsaturated air created by the boiling or rapid yvaporization of the moisture in the cloth when it is subjected to radiant heat. Under these circumstances the moisture is removed y by boiling rather than by absorbing it into the air, the air, if any, in contact with the cloth being saturated with steam. Another consequence of such treatment has been to fill the room in which the machines are installed with steam and moisture from the` -cloth under treatment, to the detriment of health and ruination of machinery. A frequent consequence has been the imperfect and irregular drying of the cloth because of operations attempted to be carried out in an atmosphere variably saturated with the expelled moisture from the cloth. Much the same difficulties have heretofore accrued when the treatment is of other materials than cloth, such as paper ortextil'e fibrous stock, or when thev drying is incident to carbonizing, or to other sta e-products ,of chemical treatments, the aci or alkalinebearing material then delivering up destructive vapors, and being irregularly aected by the applied heat.

When, as inthe case of some cloth driers, it has been sought to minimize these defects h enclosin the apparatus, a. greater loss of e ciency fdllowed because at no part of the fabric within the machine was it free from subjection tol moisture-laden air or steam. This has led to the operation of such'a paratus in the open air of the room in w ic has it is installed, in order that the vapor may escape; -and-this in turn has led to excessive 'loss of heat, drying machines of thej prior art requiring an excessive inflow of highpressure steam to maintain the great heat required for the drying operation. The prior art, so far as' I am aware, provides no compromise between imperfect and irregular drying in enclosed machines, and drymg with heat-damage and great waste of heat in o en machines. Y

T is invention obviates ythe above-mentioned defects, one object being to provide steps for the treatment of the material in a moist state to `dry lit progressively and regularly at any desired rate. Other objects are to provide a step for the treatment Y 'of such materiales cloth in such a manner of saturated vapor; to provide 4for the acy curate control of the temperatures to which the material is subjected, and so to avoid cost of ythe whole operation, and at the same time to avoid filling` the workroom with vapor and steam.

The invention is illustrated by specific drying machines typifying the genus of new apparatus suitable to carry out the new method orv art, which will now be explained in connection with the apparatus, although it is obvious that otherapparatus may be employed in the'practice of the method, and that the apparatus is also suitable for operations not implicit in the method.

ln the accompanying drawingsf- Fig. 1 is a side elevation partly in section on the line 1-1 of Fig. 2 of an evaporator employed in carrying'y out the process, and particularly adapted for materials in Hexible lengths, such as cloth, or materials carried by endless webs;

Fig. 2 is a plan view with the cover removed of the apparatus shown in Fig. 1;

Fig. 3 is a right hand elevation;

Fig. 4 is a vertical section on the line 1 -4 oi Fig. 2;

Fig. 5 is a detail plan view o one of the air tubes; f

Fig. 6 is a similar view showing a modification; and i Fig. 7 is an elevation parti i in section of modified apparatus particular y adapted for f handling materials m bulk.

Referring now to Figs. `l to 4:, the 'apparatus comprises a drying machine (or a stretching-and-drying machine) which so far as means for supporting and conducting the web or cloth through the machine, for

driving the supporting and conductin means at a desired predetermined spee and so far as the construction and operation of the mechanical or operative parts is concerned, may be any desired machine, such as those common to the'prior art. As illustrated the machine comprises any suitable macliine frame having therein bearings for an idler roll 1 (Fig. 1), for suitable transverse shaft having sprockets 2, 3, 4, 5, 6, 7, 8, 9 and 10, forl endlesscarrier chains 11 traveling with the margins of the web or cloth and an idler roll 12. Any one '1 of the sproclret shats,for instance shaft2,

maybc driven to drive all 'of the others and the carrier chains 11. .These chains 11, Fig.

1, may be of any type known in the art, comprising' gri pers, clamps, or tenter-,pins

.y or hooks to ta e into thev selvages or the lcloth l(or thematerial-carrying web) and holdit laterally open or. stretched during progress through the machine. The cloth indicated at C moves in the direction of the arrowhead at a speed predetermined for the state of saturation of the cloth whenv it enters the machine and the desired state of dryness when it leaves the machine.

The machine comprising the sprockets 1 to 10 over which the chains 11 pass is housed in av treating chamber 14 enclosed by a relatively tight heating-insulating casing having an entra-nce passage 16 (Fig. 1) for the web or cloth, which passage may if desired be protected by leather or rubber flaps 17, and having an exit passage 18 which may if desiredfbe protected by similar flaps 19.

The insulating casin comprises side walls 15El and 15b respective y spaced vaway from the machine frame by a substantial distance as best shown in Fig. 2. These walls may comprise uprights 20 of wood or metal, an

inner sheathing'21, preferably of asbestos wood or other heat-insulating and moistureresisting material, an exterior sheathing 22 of the same or any preferred materiahand if `desired a heat-insulating packing 23 in the spaces between the'uprights 20 and adjacent to the inner wall 21, and preierably rights 20 and the jomts covered with sealy ing strips 25. Any other construction which will provide a heat insulatin wall of high resistance to conduction an substantially air-tight uality may be employed.

The en wall 15' at which the web enters and leaves the machine may be of the same construction as t-he walls 15a and 15b; the other end wall 15d may be of the same construction but extends less than the entire width between the walls 15' and-15", leaving vertical openings 27 and28 'at either side of the machine. tlhe opening 27, leads into a chamber 30 set olf within the casing 15 by a vertical partition 31 preferably erected lon vertical angle-irons 32, 32, extending from the Hoor to the top v15e of the outer casing.

The chamber 30 is an entrance or plenum chamber for circulated air currents presently to be explained. The partition 31 may be of asbestos wood, orv metallic,lor of indurated fibre or a metal protected by a heat insulating aintor layer, and is utillzed as the support or a number of hot-air distributing ducts35 communicating with holes in the partition 31. These vducts are arranged in substantially horizontal rows which arev vertically spaced to lie respectivel between the several runs of the chain 11.

n the, drawings but two ducts of each row,

ill)

audace are shown to avoid confusion of illustration.

Preferably as shown, these are conical tubes A (see Figs.- 2, and 6) having flanges 36 at their larger` ends and having therein in an axial direction an educt port 37. This port may be a tapered slot 37 wider toward the lwider end of the tube 35, so that a blast enteringthe inner cavity through the open end, and increasing in pressure toward the i closed further end 38 ci the tube, will be ed byportions of the wall of the tube. lhe

Yea

distributing conduits or tubes are preferably made o-indurated libre, ot asbestos wood., or of any suitable heat and moistureresisting composition or metal, preferably adapted to be molded to shape. The smaller ends of the tube 35 may if desired be in-V i tegrally lclosed or open, closure it open being ected by mounting the ends as in sockets attached to a vertical partition 42 like the .partition 3l, and extending from the wall l5@l of the casing to the wall 15 and extending from the loor above the position of the topmost run of cloth carried by the chains. ll, leaving a narrow space between the top of the partition 42 and the top 15e of the heat-insulating casing through which space air taken into the cloth-treating chamber 14 defined by the partitions 31 and 42 can make its exit.

Any-desired part of the space 45 toward the righthand side of ll ig. l may be closed by a stop 46. The space 48 between the partition 42,l and the wall 15b of the casing is an educt chamber through and from which moisture-laden air making its exit through the s ace 45 is removed by suction or pressure rom the casing. Pressures in chamber 48 are preferably arranged to vary from plenum at and near the opening 45'to less than atmospheric ressure at and near the educt opening 28, ut it will be understood that the pressures mentioned are relative only, and may be of any value suitable to cause the desired circulation of the air in the apparatus. This chamber 48 may and preferably does contain condensation or other drying means for the extraction from the air of 'its contained moisture or vapors.

Referring to Figs. 2 and-4, any desired condensing means may be employed, but l prefer a large surface of cold metal against which the vaporor moisture-laden airv pours and through' which itl is 4caused to dow. Preferably these surfaces arevin the torni of pipe coils 50 having Coldwater inlets at 5l from asuitable cold water source [such fas a city water supply] and having -outlets into a common out1et 53. The outlet ,53 may deliver tothe wet roomor to the' boiler feed ofthe plant in order to conserve the heat transferred -to the water in VVthe coils 50 from' the airl movin in the chamber 48. The condensate liquid taken out of the airin the chamber 48 collects in suitable troughs-55 and drains ed through pipe connectionsto a common drain 56. This condensationli uid Vmay be treated to recover contained acid when'the apparatus is used "for carbonizing purposes, or to recover volatile solvents.

ln orderly practice of the new process, the air from the' chamber 48, dried by condensation, is removed from the chamber 48 through the opening 28, is reheated to the desired predetermined temperature, and is then delivered to the plenum or blast chamber 30 through the opening 27.' F or this purpose the apparatus comprises a connector casing 60, a heatingv casing 61, a delivery casing 62 and a blastolan 63 of any desired type, adapted to be driven, as byV a belt on pulley 63a, and which is so connected as tol exhaust vthe heated air from the heater 6l and deliver it at the desired plenum or pres- 1 sure through the casing 62. The casings 60, 6l, 62, and the tan 63 are all preferably of heat-insulating material, or of metal covered by an insulating layer, lagging 'or plastic' of any desired kind.

The heater 61 may contain any desired plurality of steam coils 64, 65, 66, preferably connected to steam drums or headers 67 outside of the heater 6l through separate supply pipes 68 and 69 connected by crossover 70 and individual valves 71, 72, 78, to

the respective headers. 'llhe discharge side ot the steam coils 64, 65, 66, may be provided with valves 74 outside ot the heater 6l, in the arrangement as shown, the coil 64 belUii ingfdirectly connected to the return pipe 75.

Preferably the pipe 68 is controlled by a` hand valve 76 and the cross-over 70 is controlled by hand valves 77; the pipe 69 is controlled bv an automatically, preferably pneumatically actuated valve 78 connected by air pipe 79 to a thermostat 8O of any suitable or known air-pressure-control typel supplied from a constant source of air pressure through the pipe 81. The thermostat 80 is mounted on any convenient place in the casing for instance on the under side of the cover 15e. The Vthermostat and the connections tor controlling by it the valve 78 'may it desired be any othery type, such as any of the well-known electrical circuit-controlling tyres f When the cloth is excessively wet, or the `i'romthe-.air circulated. Oneway of doing -this is to provide for the escape-of a regulated portion. of the air from the casing, after it has taken up `Ythe moisture in the cloth, and to permit the introduction into the' system of a corresponding quantity of dry air, asf from the room in which the machine is installed.

Devices for eifectingfsuch regulated escape fron/rand entrance to the-circulatory system of moist. anddry air may'A comprise a moist-air'educt pipe 90 leading. out of doors.

i A port 91- leads from a part of the chamber l' 48 in` which the air-pressure is a plenum orrEntrance o f air to the system is controlled by ya'damper or valve 95 placed at any oint where 'the pressure is less than atmos'p eric v'or negative; as shown, to control bpenings* in the casing 60. Valve 95 may be adjusted many convenient manner. Normally, the

`valves and 95 remain closed.

The method or art and operation of the apparatus willnow be clear.` -To explain the drying. of cloth C [for an instance of gravity on vthe chain-clamps or. pins. The

I the operation applicable'jto materials of any nature held en or between an endless web or webs traveling in theA path of the chains] the wet cloth, 'held upon vthe chains 11a-s' *usualv by impalin'g.` the selvages upon the tenter-pins (or catching the selva'ges-witli'in the' clamps) on the chains 11 enters 'the opening' 16 and .passes tothe top ofthe treating chamber 14.' Here itA comes into contact with the heated and dried air supply maintained within the chamber 14by the operation of the heater 61 `-and the fan`63, the` supply .in the device shown being delivered inthe form of uniform fiat blasts through the portsin the conical pipes 35. The distribution of the ports 37 in the pipes 35x11 of the first rowis such aste deliver a blast upwardly and near which the entering cloth passes', and downwardly against the adjacent face of the cloth supported by blast, delivered upwardly against the bottom v face of the cloth by the remaining pipes 35 is of aid'in maintaining the cloth .on the carrier` chains lwhen ,the chains are abovethe cloth, The lateraldistribution of the blast-[through theislots or equivalent openings] in thetuhes. 35 an 35 is uniform and the drying eifectupon the clothis coii.- sequently uniform-1L Drying byfevaporaf v tion, not by boi-linggiinder -radiantheah The cloth continues tol v .adlitg pipes 35 delivering blastsjo nal.;- riferiti, airs1 um it finally vlesivas the over; the

' Lindauery idle roller 12 and through deepening-1s" is caused to travel in a closed air circuit,

which in the apparatus illustrated is made!) up of treating chamberv 14, chamber 48,

opening 28, connection 60, heater 61, fan 63, 75 jY In travelingin this circuit the air takes up *l Y' connection 62, chamber 30, blast pipes 35.

the moisture in the cloth in the outer casing,

delivers this moisture to the condensers 50,l .Q is sucked, away fromthe condensers 50 through the rconnections 60, is reheated to a j predetermined temperature Yin the heater 61,

and is then delivered at the desired pressure in the plenum chamber 30. The cycle employed saturates the air inchamber 14, dries it in chamber 48, reheats it in heater 61 into a moisture-absorbing condition, and recovers ,l

all except the used heat in .thecondenserr water withoutsubstantial loss, owing to thel Large economies 06 Y heat-retaining casin flow from. this cyc e ofv treatment; 'the amount of heat required in the heater is l i' much smallerthan that required to contmw,

ously heat a fresh supply of air, or to supply the great losses by convection and radiation characteristicof the practice heretofore followed. An even more important result is the automatic and accurate'. control of thel ;I. temperature and hygrometr-ic condition of un.iform',instead of the variabl'eand oftenY 'damaging'results of the prior practice. l' It is preferred toregulate` the temperature. v

the treating air, by which the conditionin of the material treated is made certainan of the air l'automatically'. --The thermostat 1 valve` 78 the Howof `steam into. one or more of the steam coils 64, 65, 66. If -debe isolated fromy the .regulating means .by turning valve 77 [or tlife'valve 77 and valve coil 65 orpbotli directly with live steam through the pipes 68 as regulated by the hand valve 76, 'or cut-ting them out of the system, as required by thev variations Ain iis heat replenishment needed by the system for i any particular class of work.v vWhether the .f ythermostat controls lthe steam supply for allv three coils or for ltv'vo of them or for one 'r only, the apparatus when adjusted to the particularfwork to be done operates autoiiiatically by increase and decrease of `the ,i effective heat to maintain thedesireddegree r of temperature v'inthecirculatn "air at a 1 28 substantially, v constant 'gurex.; mee 'the l jtemperatureat the thermostat is: aiecbcdb `variable niosti'irey content in the. 'inatena the: apparatus f. automatically provides more J L orv lessvheat for theabsorption of. morel or' vless f moisture. j Conditions within i'il`1e`l 5 1,

V80 accomplishes this bygdetermining at the 'lil I 116, loose material placed on the belt 116 ramene chine may be observed by any suitable thermometers and hygrometers conveniently placed, not shown, it so desired.

'.lhe art or method and the generic class of apparatus are equally applicable to treating materials in the bulli, either as suggested above by placing such material on an endless web running'through the apparatus of Fig. 1 on the course oit the chains 11, or by including the material between perforated belts or carrier webs in the same course. I)The lrind et carrier, in other words, by which the material to be treated is circulated in the treating chamber ld may be varied to suit the particularworh in hand.

hor instance, as shown in lPig. 7, the treatment chamber 1d may be dened by insulatin walls 11b, ci the same construe tion as a ove described for the walls oi the outer case and within the chamber so formed and in the same relation to artitions 31 and d2 as described in connection with Fig. l separate endless carrier belts 1.16, 117, 113, may be arranged tor rotation on pulleys or rolls 120, 121, 122, 123, 12d, 125, one roll of each pair being driven by suitable means not shown. 'llo cooperate with carrier belts 113, 117, 118, a feed lattice 130 may enter the treatment chamber 1d, delivering' onto a guide plate 131 and thence onto the belt falling at the right side of the ligure upon `an inclined baille 132 guiding the material to the belt 117` which in turn delivers to an inclined bams 133. 'lhe material passes rbm the badie `133 to the belt 118. Any suitable number of such carrier belts may be arran d. rlhe lowermost carrier belt as shown, the belt 118, will deliver to a suitable delivery conveyor such as the lattice 126.

The circulation of air through the chamber lll is the saine as before, the pipes 35 securing within the chamber the proper distribution of warmed vand dried air circulated through the heater 61 and the air drying means, the temperature being controlled by the thermostat as above er plained.

A practical advantage of the apparatus and method Hows from the lower temperature eidective to do the work of drying by the use of regenerated air. This not only avoids heat-damage to the cloth, but is also a great economy. The degree of heat required in the heater 61 is easily maintained by exhaust or low-pressure steam or hot water from the engine room of the plant under all conditions of usual employment of the apparatus.

en reference is made herein to drying the material, it is not to be understood that all or the moisture or wetness, as of water, a 4solvent or any applied liquid,`is necessarily removed., The method described ,nl r mits the removal of any predetermined i i ction only ci the volatile or absorbable liquid contents, according to the adjustment of the condenser, the heater, and the rate oit the blower 63.

ll claim:

l. The art oi drying materials which `comprises exposing the material in a heat insulated chamber devoid oi other heating means while subjecting it to the action oit a plurality ezt blasts oit preheated dried air severally impinging upon the material, the l air moving in a substantially closed air eircuit, forcibly causing circulation of the air contained in said air circuit, treating the air in the circuit after contact with the material to remove absorbed moisture therefrom, and again warming the air before delivery against thelmaterial.

2. lin material treating apparatus, the combination oi a casing comprising therein anair-circuit including a treating chamber, means for, Supporting the material in said chamber, means for circulatingv air through said circuit, means for causing a plurality of blasts of V'the circulating air to impinge upon the material within said chamber, and means iorremoving moisture from the air operating .between exit oi the air from said lhamber and return of the air to said cham- 3. Drying apparatus having therein a drying chamber comprising heat-insulating walls, ingress and egress gates therein Vfor lthe material to be dried, means for supporting and moving the material through the chamber, a plenum entrance chamber divided from the treating chamber, and means tor heating and blowing through said chambers in contact with the material a stream ont warm dry air comprising jet tubes communieating with the plenum chamber and having orifices for directing a plurality ci blasts upon the material. v

4i. Material treating apparatus having therein a treating chamber, a plenum entrance chamber, means for maintaining air in said entrance chamber at a predetermined temperature and pressure, means for supporting the material in the treating chamber, means for heating air delivered to said ill@ Mitt

lill

entrance chamber, and a plurality of separate blast orilices delivering toward the Vmaterial within the treating chamber and communicatin'g with the entrance chamber for' means for heating and blowing through said chamber in contact with the material a current of Warm dry air, said blowin means in# cluding a plurality of separate b ast-devices delivering air-blasts laterally uniform in air circit a Chamber hav; .Y g heat-insulating walls, means fOTSUPPN" Ing the material in the chamber, and means for` heating and blowing into' said chamber and into contact with the material a plurality of blastsof warm/dry air, and means for regulating the temperature of the air blasts, operating as a'- consequence of the temperature-in thev treating chamber.

. 8. Material-treating apparatus' having 25 therein a casing comprising therein a' treatv in chamber,gmeans for .supporting mate-` ria saidchamber, a series of air-ductsde- 5 llvermg air into said chamber andupon the material therein, means-for removing moistv t #.0

air-from the chamber, and delivering the air to said air-ducts,v4 and drying means for the air operating between exit'of the air from chamber. 'y

9. Material treating apparatus having l therein 'a1 substantially closed casing enclos- L ing'an entrance chamber, `a treating chamber, and an -educt chamber; a series of ducts delivering air from` the entrance chamber against materialv in the treating chamber, means for drying the air, and means or moving the air past said drying means, from `the yeduct chamber, and into the entrance i chamber. at a predetermined rate independrent of the convection currentsdue to heatmg. v if l -Y 10.A Material treating' apparatus having therein'a substantially closed casing `enclos' ing-an entrance; chamber,ja treating 'chamvdelivering airy from theentrance chamber determined plenum pressure in said entrance a -v said chamber, air-ducts@ "naar, the` fakenbythef materialyiandzneans for. 0

K7. Drying apparatus having therein an said chamber'and' return of the airfto said lf ,b eig'jand an educt chamber a series of ducts" again'st .material inv the 'treating chamber,; `means ,1n the educt chamber for drying the ,chambeaformovingthe air.` 'ast'saiddfys' eanafrom thee-ducten@ r, and ma 17- Driving apparatus combinatiom-jm'echanism adapted to 'sup-g I #Timing Chmb #165.118, fOr-mov* he in -afconstant each' of lSaid. ducts.' the A* material a lflat stream of warm dry air, said stream in a direction lateral 0j the path taken by the material being uniform in re` spect tothe quantity of air deliveredratany part of the stream in a given time.

12. Apparatusfor treatin webs of ted enclosure having therein-means for drying a web ofv rial comprising a heat ins material comprising means for moving the web While supporting it out of substantlal contact' with heat radiatin solids, series of air ducts nearthe path ta en. by thegvveli' i and means for blowing from each 01:' "sai -ducts upon the cloths, ilat stream of warm -dry air, said stream in a direction lateral of the path taken by the web being substantially uniform in-respect to the quantity of air-delivered at: any part of the stream 1n a v given time.

13. `In drying apparatus, means for blowing a uniform stream of air onto the mate` rial to be dried comprising an air-duct having therein a lengthwise air delivery rt of varying width, wider at parts .of the uct subjectA to lesser air-pressure, and narrower at parts subject to greater air-pressure, and means for supplying air under 'pressure to 'that end of said duct at which said port is widest.

14. In drying apparatus, means for blowing a uniform stream of air on to the material to be dried comprising an air-duct subject to-air pressure atene end, and having a longitudinal air delivery port vary' inversely inwidth in s b stantial accor ance with the rise of air-pressure in wardits other `closed end.

ing a uniform stream of air on to the maand move :the material to be dried in aA series of parallel runs, aheatinsulating` casing surrounding vsaid mechanism, and means for projecting a plurality of flat jets-of heated 'air against the several runs .of material with- `in* the. casing, said jetsbeing to the quantity of air delivered at lany'part ofthe stream in a giventime, and f being directed v`fsubstantially`l perpendicuflai'ly the' face of the material.`

having therein, m'

p"or t `and'move a web of material vtolbe dried in a -pluralityj'off parallel runs, a heat-in 15. In drying apparatus, means for blowthe tube tol uniform in sulatingcasing surrounding said mechanism', L

.means `for delivering blasts of heated air of substantially funiformx Vtemperature against ,the several-mnseffthe web casmalto be dried-comprising a conical air- 195 ing, and means for automatically controlling the temperature of such blasts in response to the temperature Within the casing.

18. Drying apparatus having therein, in combination, mechanism ,adapted to suport and move a web of material to be dried 1n a series of parallel horizontal runs, a heat-insulating casing surrounding said mechanism, nozzles disposed between the several runs of material for delivering successive blasts. of heated air against the web at spaced points in the length'thereot, a heater for the air, and thermostatic means having a sensitive element Withinthe casing for controlling the heater.

19. Drying apparatus having therein, in combination, mechanism adapted to support aweb of material to be dried in a vplurality of horizontal runs, means to subject the several runs of material to the successive action of currents of heated fluid otsubstantially uniform temperature whereby to dry the material, and an insulating casing surrounding the mechanism and adapted to conserve the heat of its contents, including the material under treatment.

20. ln cloth ldrying apparatus, a heat- 'insulating casing adapted to surround mechanism for moving and supporting the drying cloth, and means dividin the casing into a centrally disposed 'c oth-treating chamber containing the mechanism, an enfl trance chamber to one side of the cloth-treatmlg chamber, and an educt chamber on the ot er side thereof, the structure comprising means for discharging air from the entrance chamber in a series of blasts against the cloth, and means for causing an' .to dow from the treating chamber to the .educt chamber and thence to the entrance chamber. 21. A cloth drying apparatus comprising paced Walls of asbestos Wood sheets assemed in substantially air-tight relation, means torsupporting said Walls in surrounding relationship to mechanism for sup`= porting and moving the cloth under treatment, and means Within said apparatus tor 22. A cloth-treating apparatus comprising spaced Walls of asbestos vvood sheets assembled in substantially air-tight relation, yan intervening packing adapted to resist loss of heat, means for sup orting said Walls in i surrounding relationship to mechanismsv tor supporting and movin the cloth under treatment, means Within said Walls for continuously circulating the air, for heating such air, and tor delivering such air in the form ot heated blasts perpendicularly against the surface or the cloth to be treated.

23. Apparatus tor drying materials comprising a heat insulating housing having therein means for subjecting the materialto be dried to' the absorbent action of successively acting blasts of gaseous Huid of substantially uniform temperature adapted to evaporate the moisture .from the material, and means for continuously circulating lthe fluid within the housing and for treatin the :fluid beforeA its access to the materia whereby to remove contained moisture from such duid, the chamber .being devoid of other heating means than the blasts.

24. Apparatus for drying comprising a heat insulated housing having 'a material treating chamber and an air circuit through such chamber, means Within the chamber tor lsupporting material out ot contact with heat radiating solids While being dried', said circuit comprising a series of uniformly ,treated air blasts, a. cold condenser in said circuit, and a heater in said circuit, said heat insulating housing substantially enclosing said air circuit, condenser and heater, Where Sti by otherwise wasted heat is conservedand usefully employed in raising the temperature ont the condenser Water.

Signed by me .at Boston, blassachusetts,l this thi-rd day ont ctober, 1919.

JOSEPH H. "lldlhlil,v 

